Escudo de la República de Colombia

English

Primers follow trace of migratory fish

By designing novel tools which use genetic information, Universidad Nacional de Colombia (UNal) in Medellín, researchers have expanded research of the ray-finned fish, the pataló, the catfish and other ten species which thrive in the Cauca River. This new development is a contribution to the genetic diversity of freshwater fish in Colombia.

Medellín, 27 de diciembre de 2016Agencia de Noticias UN-

The trans-Andean shovelnose catfish (Sorubim cuspicaudus) was one of the fished studied with the genetic tools. Photo: www.espaciodepesca.com

The research project has helped delve deeper into the study of fish which inhabit the Cauca River.

The species thrive in an area where the hydroelectric dam will be built, the largest in Colombia.

Dam building breaks the migration of a rheophile species, meaning fish that prefer to live in fast moving water.

With this contribution, researchers of any place around the world may study fish genetic diversity.

With this new technique, it is possible to obtain new information thanks to the project carried out by four UNal-Medellín graduate students directed by School of Biosciences Professor Edna Judith Márquez Fernández.

To amplify DNA regions, the researchers developed specific sequences known as “primers” which help observe population genetic variations of fish of the medium and low basins of the Cauca River, between the municipality of Tarazá and the outpour of this river into the Magdalena River.

The method accurately analyzes the genetic diversity of 13 migratory species: jetudo or pataló (Ichthyoelephas longirostris), ray-finned fish (Prochilodus magdalenae), vizcaína (Curimata mivartii), dolphin catfish (Ageneiosus pardalis), trans-Andean shovelnose catfish  (Sorubim cuspicaudus), chango or mueluda (Cynopotamus magdalenae); capaz (Pimelodus grosskopfii), arenca (Triportheus magdalenae), sabaleta (Brycon henni), four-lined pimodella (Pimelodus blochii), stripped catfish (Pseudoplatystoma magdaleniatum), schultz's bumblebee catfish (Pseudopimelodus schultzi) and comelón (Leporinus muyscorum).

These species thrive in an area where the hydroelectric dam of Ituango (Hidroituango) considered the largest hydroelectric project in Colombia will be built.  This dam could impact the migration and reproduction of fish, and ultimately contribute to loss of biodiversity.

The Universidad de Antioquia National Genome Sequencing Center performed the sequencing of the genome of the species studied to identify the primers.

According to Márquez, these tools were designed for microsatellite sequences (short repetitive DNA sequences) amply distributed throughout the genome and variable.

“For genome sequencing, we used 454 FLX pyrosequencing and Illumina next-gen sequencing, novel technologies which enable large-scale DNA sequencing. First, we analyzed the biological information and later carried out a laboratory assessment. This project which will end in 2018 will help us understand genetic diversity and if there has been a connection between species,” added Márquez.

Partial results have shown that from the genetic point of view, the individuals of a particular species from one part of the basin are different from those of another part of the basin.

Although the project did demonstrate that several short (up to 100 km, [62 miles]) and medium migration species (between 100 and 500 km [62 and 310 miles]) are genetically similar; the analyses continue for the ray-finned fish, the capaz and the four-lined pimodella, species which have successfully passed the location where the dam is being built. This will help obtain information to estimate the potential changes in genetic diversity of the populations.

Tested at Hidroituango

According to Social and Environmental Biologist Hernán Sánchez Cruz, of the Hidroituango Environmental and Sustainability Directorate, one of the most important effects of this type of projects is that it creates a sort of barrier effect for fish.

“Building dams breaks the migration of rheophile (fish that prefer to live in fast moving water) individuals which carry out their reproductive processes upstream,” he said.

However, the projects discovered that this break or lack of connection is provided naturally because downstream there are 26 whitewater streams which are a natural obstacle for fish migration.

Sánchez adds that this is an important discovery as other studies in dams have focused only on the most representative species and in this research project they analyzed all migratory fish of the area to design effective management measures. This offers reliable information for all the inhabitants of the region which fears building the dam will impact fishing.

Fish barcoding

Among the results provided by the research project is the amount of data of other species which had not been studied in the past, some of which are endemic to Colombia. Such as the case of the jetudo of which the researchers obtained information on their reproduction and ecology.

Furthermore, the project also assembled mitochondrial genomes which had not been discovered before in the world and identified species using a procedure known as Fish DNA Barcoding which helps determine if individuals are of the same species or not.

Another aspect of the project contributed to verify that in a species of catfish differences between individuals are not recent but on the contrary are millions of years old. According to Márquez, this is probably because this basin was most likely a great pool and when the Andes Mountains emerged they interrupted the natural connection between species.

“This is interesting data because if one does not know of the changes before building the dam we could think this is a recent issue due to the construction. The following stage of the project will be establishing the phenotypic variation to become cognizant of the body changes and species adaptation,” she said.

(Por: end/
)
N.° 49

Otras noticias

Educación

junio 23 de 2018

Las lecciones de la reforma de Córdoba

Del 10 al 15 de junio pasado, más de 1.000 personas de distintos países se...

La profesora Claudia Patricia Pérez Rodríguez recibió el reconocimiento en representación de la rectora de la U.N., profesora Dolly Montoya Castaño. Fotos Nicolás Bojacá/Unimedios

Educación

junio 22 de 2018

U.N., la institución que más datos aporta sobre diversidad biológica en Colombia

El Sistema de Información sobre Biodiversidad de Colombia (SIB Colombia)...

El Consejo Académico se reunió en la Hemeroteca de la U.N. Fotos: Santiago Rodríguez / Unimedios

Educación

junio 22 de 2018

Consejo Académico nombró a los integrantes de los Comité Nacionales

Entre los temas tratados en la primera sesión del Consejo Académico, al que...

Salud

junio 22 de 2018

Los golpes del fútbol

Aunque el fútbol no es un deporte de alto riesgo, los futbolistas profesionales...

Para un diseño web inclusivo se debe conocer a los usuarios, su interacción, los actores que intervienen y los elementos de usabilidad de la interfaz.

Ciencia & Tecnología

junio 22 de 2018

Diseño web incluyente para adultos mayores

Aplicar la metodología de diseño conocida como Design Thinking permitiría...

El equipo de la U.N. compartirá en Italia sus estudios sobre la carrera Séptima de Bogotá.

Educación

junio 22 de 2018

La U.N. lleva la carrera Séptima a la Universidad de Bolonia

Tres profesores y un estudiante del Departamento de Arquitectura y Urbanismo de...

El desempleo juvenil en Colombia fue del 18,7 % en primer trimestre de 2018. Foto: Nicolás Bojacá.

Economía & Organizaciones

junio 22 de 2018

Desempleo juvenil, entre la baja oferta laboral y la informalidad

La experiencia como la principal barrera que esgrimen los jóvenes para...

La innovación fue el factor principal para que los trabajos de los docentes participantes fueran aceptados en el congreso internacional.

Educación

junio 22 de 2018

Modelos educativos de la U.N. en Arauca son destacados en Argentina

El juego, los materiales reciclables y la cultura llanera como herramientas de...

La construcción de pluviómetros es una de las actividades realizadas por los niños y jóvenes.

Ciencia & Tecnología

junio 22 de 2018

La U.N. enseña ciencia para colegios de Manizales

Estudiantes de instituciones educativas de esta ciudad construyen pluviómetros...

Los estudiantes esperan crear una empresa que se dedique a la enseñanza de estos conceptos.

Educación

junio 22 de 2018

Bloques de armatodo para aprender conceptos básicos de electricidad

Por medio de una herramienta lúdica denominada ElecLab, los estudiantes de...